Acquisition of Kleer Lumber (Details) (USD $)	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Estimated fair values of assets acquired and liabilities assumed
Goodwill	$ 137,198,000				$ 116,671,000				$ 137,198,000	$ 116,671,000	$ 116,671,000
Intangible assets acquired:
Revenue	214,985,000	197,030,000	140,988,000	149,573,000	190,107,000	175,621,000	129,632,000	137,427,000	702,576,000	632,787,000	587,964,000
Net income (loss)	10,253,000	11,016,000	(8,260,000)	(5,872,000)	(4,906,000)	(13,036,000)	(20,558,000)	(23,748,000)	7,137,000	(62,248,000)	(229,921,000)
Kleer Lumber, Inc.
Acquisition
Total cash consideration of acquisition				43,300,000
Fees for advisory, legal and other professional services	900,000								900,000
Estimated fair values of assets acquired and liabilities assumed
Current assets				5,818,000
Current liabilities				(3,093,000)
Property, plant and equipment				4,098,000
Goodwill				20,527,000
Net assets acquired				43,250,000
Intangible assets acquired:
Period over which goodwill is expected to be deductible for tax purpose									15 years
Revenue									28,600,000
Net income (loss)									1,600,000
Pro forma consolidated revenue and net income (loss)
Revenue									709,982,000	670,682,000
Net income (loss)									8,834,000	(63,095,000)
Nonrecurring expense related to the fair value adjustment to acquisition-date inventory					500,000					500,000
Other costs	300,000								300,000
Kleer Lumber, Inc. | Trade name
Intangible assets acquired:
Indefinite lived intangible assets				4,800,000
Kleer Lumber, Inc. | Customer Relationships
Intangible assets acquired:
Finite lived intangible assets				$ 11,100,000
Estimated useful lives				15 years